Orphan Black is returning to the BBC tonight, 14 months after the UK broadcast of the Season 2 finale. The whole of Season Three will be available to watch on BBC iPlayer from 10pm tonight. Episodes will also be broadcast on BBC Three in the early hours of the morning, also known as the 'graveyard slot'. The channel will be airing double bills starting this Sunday at 2:10am with The Weight of This Combination followed by Transitory Sacrifices of Crisis.

Sarah tries to bluff a ruthless enforcer that all is well at the Dyad Institute, while Alison's family finances pose problems. Helena is prisoner of the Castor clones, one of whom poses an immediate threat to those Sarah holds dear.